Biopsychology: Key Terms Flashcards
Nervous System
- a connected system of nerves that run throughout the body connected to one another by synapses
- carry messages to + from brain + spinal cord to body
- 2 functions: to collect, process + respond to info in environment, to coordinate the working of different organs + cells in the body
Central Nervous System (CNS)
controls behaviour + regulates the body’s physiological processes
Brain
centre of all conscious awareness
Spinal Cord
- relays info between brain + rest of body
- allows brain to regulate bodily processes
- body of nerve fibres inside armoured conduit in spine
- some neural processing (reflexs)
Somatic Nervous System (SNS)
- branch of peripheral nervous system
- voluntary movement
- relays nerve impulses from CNS to rest of body + back
Autonomic Nervous System (ANS)
- branch of peripheral nervous system
- control of involuntary automatic processes
- connects brain to organs and glands
Sympathetic Branch
- branch of ANS
- increases energy
prepares body for physical activity by activating adrenal gland to release adrenaline so liver produces glucose, breather more, heartbeat increases
Parasympathetic Branch
- branch of ANS
- conserves energy
- slows down what sympathetic branch speeds up
- stimulates digestive system
Function of the Cerebral Cortex
cognitive functions
Function of the Diencephalon
conduct housekeeping functions (getting thirsty + hungry at the right times, body temperature)
Function of the Cerebellum
- skilled motion (football, signing name)
- balance
Afferent
bringing info towards brain
Efferent
taking info away from brain
Parietal Lobe
processes sensory information
Frontal Lobe
thought + production of speech
Temporal Lobe
organises sensory input eg speech
Brain Stem
regulates automatic functions eg breathing
Neurons
- specialised cells that receive info + transmit it to other cells
- by transmitting signals electrically they provide the nervous system with its primary means of communication
Nucleus
contains DNA for genetic code for body
Cell Body (Soma)
contains organelles such as nucleus
Dendrites
- collect info and feed it into nerv cell
- connected to soma
Axon
transmits info from dendrites to another part of CNS or body
Myeline Sheath
fatty layer (insulation) around axon that speeds up transmission
Axon Terminal Button
- nerve endings
- where action potential ends up
- make synapse with dendrite of another nerve cell
Action Potential
electrochemical pulses that run down axons
Firing Rate
- how many actions potentials travel down the axon per second
- up to 200Hz
Sensory Neuron
- collect info from each of 5 senses + transmit it into the CNS
- part of an afferent pathway
- dendrites connect with sensory receptors
Relay Neuron
- completely internal to CNS
- connect one neuron to another
- no myeline sheath
Motor Neuron
- take commands from motor cortex of brain out to muscles + control movements
- efferent pathway
- dendrites connect to motor end plates on muscle fibers
Receptor Cell + Example
- collect info from outside world
- eg specialised photosensitive receptor cells in the retina collect light and transmit nervous impulses into sensory neurons in optic nerve
Motor End Plate
when the firing rate is increased the muscles then contract and when its decreased the muscles relax
Vesicles
- tiny sacs
- contain neurotransmitters that travel across the synaptic cleft
Presynaptic
- before the synapse
- delivers info into the synaptic cleft
Postsynaptic
- after the synapse
- receives neurotransmitters
What happens to the vesicles when an action potential arrives at the axon terminal button?
it fuses with pre-synaptic membrane + deposit neurotransmitters into the synaptic cleft to go to the other side
What is exocytosis?
when vesicles fuse with the pre-synaptic membrane
What are receptor sites and what do they do?
theyre on the post-synaptic membrane and activate the post-synaptic neuron when the right neurotransmitter molecule fits into it
How do neurotransmitters cross the synaptic gap?
through diffusion
Excitation
occurs when receptor stimulation results in an increase in the positive charge of the postsynaptic neuron (depolarisation) and increases the likelihood of the neuron firing and passing on the electrical impulse
- known as an excitatory post-synaptic potential (EPSP)
Inhibition
occurs when receptor stimulation results in an increase in the negative charge of the postsynaptic neuron (hyperpolarisation) and decreases the likelihood of the neuron firing and passing on the electrical impulse
- know as an inhibitory post-synaptic potential (IPSP)
Summation
- the addition of positive and negative post-synaptic potientials
- EPSPs and IPSPs are summed and if net effect of post-synaptic neuron is inhibitory, neuron will be less likely to fire and if net effect is excitatory, neuron will be more likely to fire
Hormones
- chemical messengers in the body
- target cells have receptors for particular hormones
- when enough receptor sites are stimulated by a hormone it results in a physiological reaction in the target cell
Where are hormones made?
glands
How are hormones transmitted around the body?
- through the bloodstream
- blood p0umps hormones around target sites
Functions of the hypothalamus
housekeeping functions: makes us hungry, thirsty, wake up, go to sleep, regulates body temperature and sex drive
What is the master gland of the endocrine system?
pituitary gland
Why is it called the master gland?
- controls whole of endocrine system (all of the glands)
- releases hormones that stimulate other glands as well as own hormones
What are the major glands?
testes, ovaries, pituitary, adrenal
How does the brain communicate with the endocrine system?
- the hypothalamus is located in the brain and communicates with the pituitary gland through the infundibulum
- the pituitary then produces hormones that influence the rest of the endocrine system
How does the pituitary gland make the other endocrine glands release their hormones?
- it produces hormones that travel through the bloodstream and bind to receptor cells on other glands in the endocrine system
- this causes them to release their hormones
3 Key hormones from the pituitary gland
- posterior (back): oxytocin: uterus contractions during childbirth
- anterior (front): ACTH: stimulates adrenal cortex + release of cortisol during stress response
- FSH: stimulate gonads to release sex hormones
Key hormone from testes
testosterone: development of male sex characteristics during puberty + promotes muscle growth
Key hormone from ovaries
oestrogen: controls regulation of female reproductive system including menstrual cycle + pregnancy
3 Key hormones from adrenal glands
- adrenal medulla: adrenaline + non adrenaline: key role in fight or flight
- adrenal cortex: cortisol:
Key hormone from parathyroid
parathyroid hormone: regulates amount of calcium + magnesium in body
Key hormone from pancreas
insulin: regulates blood sugar levels
Key hormone from pineal gland
melatonin: regulates arousal, biological rhythms + sleep-wake cycle
Fight or Flight Response
an evolved response to a threat that prepares our body for physical activity
Function of the amygdala
- when faced with a threat amygdala is mobilised
- sends alarm signal to hypothalamus which activates 2 responses through the sympathetic nervous system
- associates sensory signals with emotions associated with fight or flight
What does hypothalamus do when stimulated by amygdala?
2 responses:
- SAM: body’s response to an acute stressor
- HPA: body’s response to a chronic stressor
The Sympathomedullary (SAM) Pathway
- short term threats activate the sympathetic branch of the autonomic nervous system (acute response)
- stimulates medulla of adrenal gland to release adrenaline + noradrenaline
- when threat is gone parasympathetic branch is activated
body’s initial response to stress (first 30s) - end product is adrenaline
- if body continues to experience stress the second system kicks in
The effect of adrenaline and noradrenaline
- increasing heart rate + blood pressure + breathing
- releases glucose
- prepare body for physical activity
- digestion is reduced
Why is parasympathetic branch of ANS called ‘rest and digest’ response?
enhances digestion + reverses the responses that prepare our body for activity
The Hypothalamic-Pituitary-Adrenal (HPA) Axis
- counter shock repsonse to deal with long term stress
- hypothalamus produces corticotrophic releasing hormone
- then stimulates anterior lobe of pituitary gland which produces adrenocoticotrophic hormone which travels to cortex of adrenal gland
- produces cortisol
- SAM uses lots of energy + resources so HPA tries to counter this to restore body’s state of balance
The effect of cortisol
- reduces sensitivity to pain + cognitive function so think less clearly
- reduces function of immune system in long term + make us more at risk of diseases + infection
What happens after stress?
- symptoms of sympathetic arousal will begin to subside: heart rate, breathing + temperature will return to normal
- this is due to increased activity of PNS: PNS is responsible for relaxation of body + decreased activity in SNS
- body returns to normal state of arousal
Broca’s Area
an area in the left hemisphere of the frontal lobe of the brain related to speech production
Localisation of Function
refers to the belief that specific areas of the brain are associated with specific cognitive processes
Motor Cortex
a region of the brain responsible for the generation of voluntary motor movements
Somatosensory Cortex
a region of the brain that processes input from sensory receptors in the body that are sensitive to touch
Wernicke’s Area
an area in the temporal lobe of the brain important in the comprehension of language
Contralateral
each side of the brain controls the opposite side of the body
Ipsilateral
each side of the brain controls the same side of the body
Broca’s Aphasia
- brain injury in Broca’s area
- causes inability to speak properly
- typically have halting and effortful speech filled with lots of silences
- can say content words eg nouns but can’t string them together
- same defecit in writing as in speaking
Wernicke’s Aphasia
- brain injury in Wernicke’s area
- not able to understand speech and produce fluent speech that sounds grammatically correct but doesn’t contain proper words
- have anosognosia so don’t know that anything is wrong with them
Corpus Callosum
- joins the 2 hemispheres together with 2-3 hundred million axons
- carries nerve impulses from one side to the other
“Split Brain” Patient
people with a severed corpus callosum
Tachistoscope
- presents visual stimuli in a very short flash for less than a second
- split brain patients won’t have a chace to move their head so both hemispheres can process it
- tests capabilities of separated hemispheres
- presenting a word in the left visual field is processed by the right hemisphere but the person can’t visually communicate what they saw as there’s no language centre in the right hemisphere
Plasticity
the brain’s ability to adapt and physically adjust itself as a result of experience
Functional Recovery
- how the brain can recover abilities that have been compromised due to injury
- neighbouring parts of the brain are able to take over some of the function of the damaged area
3 Ways Plasticity Takes Place
1) Synaptic Reweighing
2) Creating New Synapses
3) Synaptic Deletion
Synaptic Reweighing
- if there’s increased activity over a long period of time then the synapse can physically grow
- this means that there will be more vesicles so with each action potential more neurotransmitter is released into the synaptic cleft so a stronger signal will be transmitted to the dendritee of the next nerve cell
- they can also shrink if the synapse is under active
Creating New Synapses
- happens if the axon of one nerve cell passes really close to the dendrite of another nerve cell and forms a new connection between existing nerve cells
Synaptic Deletion
- removing or deleting existing synapses
- the main way learning takes place in the brain
- vesicles reduced to such a small number that the synapse stops transmitting anything between two nerve cells
3 Ways the Brain Recovers it’s Functions
1) Neuronal Unmasking
2) Axonal Sprouting
3) Recruitment of Homologous Areas
Neuronal Unmaksing
dormant synapses come to life and start working
Axonal Sprouting
- happens in the brains of unborn children and very young babies
- axons of nerve cells physically grow longer to link onto the dendrites of other nerve cells and form new synapses
- following trauma in older brains neighbouring areas can do limited axonal sprouting
Recruitment of Homologous Areas
the corresponding area in the opposite hemisphere takes over the function of the damaged area
Cognitive Reserve
- the minds and brains resistance to damage of the brain
- we develop a reserve of thinking abilities during our life that protects against losses eg brain trauma
- associated with having more years of eduaction so these people will have more help in neural adaptation during recovery
Post-Mortem Examination
- examining the brains of those that have died
- look at disabilities an dabilities people have in their life and then examine their brains to see if they’re different from a neurotypical brain
fMRI
- functional magnetic resonance imaging
- red parts are oxygenated blood which shows higher levels of activity
- 1 or 2 mm spatial resolution
- 1 or 2 seconds temporal resolution
EEG
- electroencephalogram
- measures the electrical activity of the brain using electrodes
- measures action potentials
- very low spatial resolution
- very high temporal resolution
ERP
- event related potentials
- first 100 milliseconds are sensory ERPs
- after 100 milliseconds are cognitive ERPs
- presents stimulus to person many times to record EEG many times then superimposes all EEGs on top of each other to reduc background noise and make ERP really clear
- very low spatial resolution
- very high temporal resolution
Temporal Resolution
the accuracy and precision of when things take place in the brain
Spatial Resolution
the accuracy and precision of measurements of where in the brain things take place
Circadian Rhythm + Example
- once a day
- sleep-wake cycle
Infradian Rhythm + Example
- slower than once a day
- menstrual cycle
Ultradian Rhythm + Example
- faster than once a day
- sleep cycle
Suprachiasmatic Nucleus (SCN)
- receives small spur of nerve fibers from optic nerve so messages in the optic nerve from the retina go to the SCN
- it signals to parts of the brain which regulate body temperature. and production of hormones (particularly melatonin)
- on top of the optic chiasm
Endogenous Pacemaker and Example
- a mechanism in the body which governs internal biological rhythms
- SCN
Exogenous Zeitgeber and Example
- an external time-giver
- and environmental cue which helps synchronise biological rhythms with the outside world
- light
